Gymnemic acid is extracted from Gymnema sylvestre, a woody climbing plant native to India, Africa, and China. Gymnemic acid is a dietary supplement sold worldwide, primarily in encapsulated forms. (See Ogawa et al., J. Food Hygienic Soc Japan (2004) 45:8-18) Gymnemic acid is known to temporarily block the sensation of sweet taste when applied directly to the oral cavity. (See Kurihara, 1969 and Sanematsu, J. Biol. Chem. (2014) 289:25711-25720). Studies have shown that subjects given gymnemic acid consume fewer calories than subjects given a placebo (See Brala et al., Physiol. Behav. (1983) 30:1-9). However, gymnemic acid is known to have an intense bitter taste that is unpalatable to humans. (See, for example, U.S. Publication No. 2004/007180).
Traditionally, in the field of flavor science, one would add a sweetener such as sucrose to a composition to mask the bitter taste of an essential ingredient. Intensely bitter ingredients would require larger amounts of sucrose or perhaps a more intense artificial sweetener such as sucralose to mask the bitterness. However, these traditional bitter blocking methods do not work to reduce the bitter taste of gymnemic acid, as a result of gymnemic acid's sweet taste blocking property. Moreover, the use of an intense natural or artificial sweetener can interfere with the desired sweet blocking activity of the gymnemic acid, as both sweeteners and gymnemic acid interact and bind with sweet taste receptors (Sanematsu, J. Biol. Chem. (2014) 289:25711-25720).
It is also common in the field of flavor science, when working with a composition containing a bitter ingredient, to prepare an encapsulated or tablet dosage form that is intended to be immediately swallowed. This approach avoids any bitterness problem because the bitter ingredient never directly contacts the oral cavity. However, such a dosage form is not feasible for a composition containing gymnemic acid, which is intended to directly contact the oral cavity and tongue, and then be swallowed.
For more than a decade, attempts have been made to develop a diet product that delivers Gymnema directly into the oral cavity. However, due to the inability of known flavor science to effectively eliminate the intense bitterness of Gymnema, these attempts have failed. One such attempt is discussed in U.S. Publication No. 2004/007180 which describes a lozenge combining Gymnema leaf extract with a de-bittering agent, disclosing the bitter masking agent as “Comax Flavors #2588E 17379.” Sugarest™ gum, manufactured by Genotec Nutritionals, Inc. was marketed to temporarily block sweet taste receptors for 20-30 minutes. (Press Release, MM2 Group, Inc., MM2 Group's Sugarest™ Featured on TV News in Philadelphia (Apr. 12, 2007), available at http://www.prnewswire.com/news-releases/mm2-groups-sugaresttm-featured-on-tv-news-in-philadelphia-58283722.html). The product failed and has not been available for many years.
Supresalin is a composition containing gymnemic acids alleging to reduce sugar cravings for approximately 30 minutes. (http://supresalin.com/faqs/). Sugar Suppress 60 is another product containing gymnemic acids that claims to reduce calorie consumption and promote weight loss. However, this product is intensely bitter and unpalatable. After many failed attempts, there remains a need for a palatable, non-bitter composition of gymnemic acid, in a lingual delivery form, that fully blocks sweet taste for an extended period of time.